How much cooling assistance from an oil cooler

Photos always help. You guys are talking about 2 different devices. An "oil to water" cooler will not increase cooling (much), but will give more uniform temperature in the engine. My T&C minivan w/ towing package has one. They are an easy add-on, bolting between filter and engine, plus a little coolant plumbing. An "oil to air" cooler will increase total cooling, w/ caveat that it takes away from airflow thru the radiator. My M-B has that, side-by-side w/ the radiator and thus mandating a smaller radiator. Most add-ons would bolt in front of the radiator, but still stealing potential air cooling from the radiator.